The present invention relates to a method of producing a stable highly pure product of a borate complex of triarylborane with alkylated or arylated alkali metal.
In the conventional production method of alkali metal ate complex of organoboron, generally (J. C. S. Perkin II, E. NEGISI et al., 32, 1225 (1978)), organoboron is reacted with organo alkali metal at 0.degree. C. using tetrahydrofuran or diethyl ether as a solvent. On the other hand, when organo lithium is reacted using tetrahydrofuran as a solvent, there is a possibility of causing a side reaction as follows (J. Organo-metallic Chemistry, H. C. BROWN et al., 188, 1-10(1980)): ##STR1##
As described above, in the conventional production method of alkali metal borate complex of organoboron, generally, organoboron is reacted with organo alkali metal at 0.degree. C. using tetrahydrofuran or diethyl ether as a solvent. Moreover, when organo lithium is reacted using tetrahydrofuran as a solvent there is a possibility to cause a side reaction.
The present invention is a result of investigations on a production method of high-yield and yet high purity borate complex of triarylborane with alkylated or arylated alkali metal. In this invention, after the synthesis of triarylborane, the ether type solvent is distilled off, thus leaving only the hydrocarbon type solvent, and then, after removing thoroughly the solidifying magnesium salt produced as a by-product and unreacted arylmagnesium halide, the triarylborane product is reacted with a solution of alkylated or arylated alkali metal in hydrocarbon type solvent, chain ether type solvent or mixed solvent thereof at -20.degree.-5.degree. C., thereby side reactions with the side-produced magnesium salt and the unreacted arylmagnesium halide can be prevented and, at the same time, the problems aforementioned can be solved, leading to the invention.